Reference · Core data & language

Collections & objects

536 functions in 76 classes, grouped by what they do, each with the explanation the library gives of itself.

The story of this area, for a general reader: what a crafter does with it, an example run and its rated lanes, is on its Platform page.

The functions, by what they do

Testing and checking

IsUpToNBoundsNamedParam ~~~~~~~~ in stzListNamedParams
composed example
```
o1 = new stzListNamedParams([ :UpToNBounds, 3 ])
? o1.IsUpToNBoundsNamedParam()
#--> 1
```
composed from the signature, run for this page
IsUptoPositionNamedParam Misspelled form in stzListNamedParams
composed example
```
o1 = new stzListNamedParams([ :UptoPosition, 3 ])
? o1.IsUptoPositionNamedParam()
#--> 1
```
composed from the signature, run for this page
IsUntilSubStringNamedParam Move IsToSubStringNamedParam() here in stzListNamedParams
composed example
```
o1 = new stzListNamedParams([ :UntilSubString, 3 ])
? o1.IsUntilSubStringNamedParam()
#--> 1
```
composed from the signature, run for this page
IsByManyOrWithManyOrUsingManyNamedParam ...Param(s) with s in stzListNamedParams
composed example
```
o1 = new stzListNamedParams([ :ByMany, 3 ])
? o1.IsByManyOrWithManyOrUsingManyNamedParam()
#--> 1
```
composed from the signature, run for this page
IsSet TRUE if all the items are unique (the list is a set). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.IsSet()
#--> 0
```
composed from the signature, run for this page
CheckW CheckW: all items satisfy a W (DSL) condition. CheckW is the same -- now that the DSL is engine-backed (the perf/expressiveness split is gone). in stzList
```
o1 = new stzList([ "A", "B", "C" ])
? o1.CheckW('{ isString(@item) and IsUppercase(@item) }')
#--> 1
```
library test
IsPair TRUE if the list holds exactly two items. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.IsPair()
#--> 0
```
composed from the signature, run for this page
IsAList So a stzList answered "no" to being a list, and every `but IsAList()` arm in the library fell past it. stzObject.IsEither() has such an arm, followed by `but IsAnObject()` -- which a stzList IS -- so comparing two lists raised "Feature not implemented yet!" from a branch meant for something else entirely. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.IsList()
#--> 1
```
composed from the signature, run for this page · written IsAList() in the library today: the host language already holds IsList(), and Haro removes the detour
Contains TRUE if the list contains the given item. in stzList
```
o1 = new stzList("a":"t")
? o1.Contains("x")
#--> 0
```
library test

IsMadeOf IsMadeOf family: "the list consists of these items". -- IsMadeOf / IsMadeOfThese -> contains ALL the given items. in stzList

o1 = new stzList([ "a", "b", "c", "a", "a", "b", "c" ])
? o1.IsMadeOf([ "a", "b", "c" ])
? o1.IsMadeOfSome([ "a", "b", "c", "x", "z" ])
#--> 1
#--> 1

library test

IsSorted TRUE if the items are sorted, ascending OR descending. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.IsSorted()
#--> 0
```
composed from the signature, run for this page

IsEqualTo equality check (set-based, engine-backed) in stzList

o1 = new stzList([ "C", "A", "B" ])
? o1.IsEqualTo([ "A", "B", "C" ])
? o1.IsEqualToXT([ "A", "B", "C" ])
#--> 1
#--> 0

library test

and 104 more in the reference

Finding

Find Find the given item: the positions of EVERY occurrence, as a list (engine-backed). (case-sensitive by default) in stzList
```
# find example 1
? @@( Q([1, 2, 3, 4, 5, 3, 7]).Find(3) )
#--> [ 3, 6 ]
```
library test
FindNth Case-insensitive word-order aliases used by narrative tests. (Cannot live inside FindNthOccurrenceCS as nested defs because they take a different arity -- top-level methods instead.) in stzList
```
o1 = new stzList([ "_", "_", "♥", "_", "♥", "_", "_", "♥", "_", "_" ])
? o1.FindNth(3, "♥")
#--> 8
```
library test
FindItem The positions of every occurrence of the item (the Find contract). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.FindItem(3) )
#--> [ 2, 4 ]
```
composed from the signature, run for this page
FindNext FindNext: convenience wrapper used by narrative tests. Accepts either FindNext(item, n) or FindNext(item, :StartingAt = n). in stzList
```
o1 = new stzList([ 1, 2, 3, "*", 5, 6, "*", 8, 9 ])
# findnext example 1
? @@( o1.FindNext("*", :StartingAt = 4) )
#--> 7
```
library test
LastItem getting the last item in the list in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.LastItem()
#--> 1
```
composed from the signature, run for this page

FindItems [[item, [positions...]], ...] in first-appearance order in stzList

o1 = new stzList([ "A", "B", "A", "C", "D", "B" ])
? @@( o1.Index() )
#--> [ [ "A", [ 1, 3 ] ], [ "B", [ 2, 6 ] ], [ "C", [ 4 ] ], [ "D", [ 5 ] ] ]

library test

FirstHalf The first floor(n/2) items of the list. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.FirstHalf() )
#--> [ 5, 3 ]
```
composed from the signature, run for this page
FirstItem getting the first item in the list in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.FirstItem()
#--> 5
```
composed from the signature, run for this page

FirstList allitemsareequalto (split-dropped / new). in stzList

o1 = new stzList([ "A", "B", 1:3, "C", "D", 4:5 ])
? o1.FirstList()
? o1.FindFirstList()
#--> 1
#--> 2
#--> 3
#--> 3

library test

NthToLast The nth item counted from the end: NthToLast(1) is the item -- before the last, NthToLast(2) the one before it, and so on. in stzList
```
o1 = new stzList([ "S", "O", "F", "T", "A", "N", "Z", "A" ])
? o1.NthToLast(2)
#--> N
```
library test
FindLargest smallest/largest positions, items-with-positions, etc. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.FindLargest() )
#--> [ 3 ]
```
composed from the signature, run for this page
FindNextNth The position of the nth occurrence of the item after the given position. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.FindNextNth(2, 3, 5)
#--> 0
```
composed from the signature, run for this page

and 105 more in the reference

Counting and measuring

Min Min / Max for numeric lists in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.Min()
#--> 1
```
composed from the signature, run for this page

Sum Sum / Product / Mean (engine-backed) in stzList

# Sum([1,2,3,4]) is 10
? Q([1,2,3,4]).Sum()
# IsEmpty([]) is TRUE
? Q([]).IsEmpty()
# IsEmpty([1]) is FALSE
? Q([1]).IsEmpty()
#--> 10
#--> 1
#--> 0

library test

NumberOfLists How many LIST items the list holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfLists()
#--> 0
```
composed from the signature, run for this page
NumberOfPairs How many pairs the list holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfPairs()
#--> 0
```
composed from the signature, run for this page
NumberOfLevels Max nesting depth (a flat list is 1 level). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfLevels()
#--> 1
```
composed from the signature, run for this page
NumberOfClasses How many distinct classes the items form. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfClasses()
#--> 0
```
composed from the signature, run for this page
NumberOfLargest smallest/largest positions, items-with-positions, etc. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfLargest()
#--> 1
```
composed from the signature, run for this page
NumberOfLetters How many LETTER items the list holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfLetters()
#--> 0
```
composed from the signature, run for this page
NumberOfNumbers How many NUMBER items the list holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfNumbers()
#--> 5
```
composed from the signature, run for this page
NumberOfStrings How many STRING items the list holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfStrings()
#--> 0
```
composed from the signature, run for this page
NumberOfSmallest smallest/largest positions, items-with-positions, etc. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.NumberOfSmallest()
#--> 1
```
composed from the signature, run for this page
NumberOfDuplicates NumberOfDuplicates counts the duplicate OCCURRENCES (every 2nd+ appearance), not the number of distinct duplicated items. For [ "A","B","2","A","A","B",2,2,"." ] that is 4 (A twice, B once, 2 once). NumberOfDuplicatedItems (distinct) would be 3. in stzList
```
oW = new stzList( o1.Words() )
? oW.ContainsDuplicates()
? oW.NumberOfDuplicates()
#--> 1
#--> 3
```
library test

and 28 more in the reference

Replacing and setting

Update Replace the whole content with the given list (mutating; the enforcement guard sits at _SetContent, the single update point). in stzList
```
o1 = new stzList("A":"E")
o1.Update([])
? @@( o1.Content() )
#--> [ ]
```
library test
ReplaceAt Positional replace: swap whatever lives at position n with pNewItem. Mirrors AddItemAt / InsertAt / RemoveAt naming. in stzList
```
o1 = new stzList([ "A", "a", "A" ])
o1.ReplaceAt(2, :By = "A")
? o1.Content()
#--> A
#--> A
#--> A
```
library test
ReplaceSection ReplaceSection: the section [n1..n2] is replaced by ONE new item -- -- if that item is a list, it is inserted as a SINGLE element. This is -- the canonical Softanza semantics (see ReplaceSectionByMany to splice). in stzList
```
o1 = new stzList([ "1", "2", "_", "_", "_", "4", "5" ])
o1.ReplaceSection(3, 5, :With = "3")
? @@( o1.Content() )
#--> [ "1", "2", "3", "4", "5" ]
```
library test
ReplaceAllItems Replace every item by a single new one: ReplaceAllItems(:With = newItem) or ReplaceAllItems(newItem). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.ReplaceAllItems(2)
? @@( o1.Content() )
#--> [ 2, 2, 2, 2, 2 ]
```
composed from the signature, run for this page

ReplaceThisItemAt positional replacers (ported from the monolith) in stzList

o1 = new stzList([ 1, 2, "♥", 4, "♥" ])
o1.ReplaceThisItemAt(3, "♥", :With = "★")
? @@( o1.Content() )
o1.ReplaceThisItemAt(2, "BLA", :With = "★" )
? @@( o1.Content() )
#--> [ 1, 2, "★", 4, "♥" ]
#--> [ 1, 2, "★", 4, "♥" ]

library test

ReplaceOccurrencesByMany Replace items at the GIVEN positions with paNewItems consumed in order. in stzList

o1 = new stzList([ "A", "B", "*", "D", "*",  "=" ])
o1.ReplaceOccurrencesByMany([ 3, 5, 6 ], ["C", "E", "F"])
? @@( o1.Content() )
#--> [ "A", "B", "C", "D", "E", "F" ]

library test

ReplaceAnyItemAtPositions Set whatever lives at each of panPos to pNewItem. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.ReplaceAnyItemAtPositions([ 2, 3 ], 2)
? @@( o1.Content() )
#--> [ 5, 2, 2, 3, 1 ]
```
composed from the signature, run for this page
ReplaceRepeatedLeadingItem Replace the run of repeated LEADING items with a given value -- (:with names it). Delegates to ReplaceLeadingItems. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.ReplaceRepeatedLeadingItem(3)
? @@( o1.Content() )
#--> [ 3, 3, 8, 3, 1 ]
```
composed from the signature, run for this page
SetValueAt NOTE // Normally Set... does not belong to Softanza semantics, we use Replace instead. Here I use to cope with AI-generated code which tend to be alligned with the Set keyword in stzHashList
composed example
```
o1 = new stzHashList([ :name = "Aya", :age = 30, :city = "Niamey" ])
o1.SetValueAt(2, 5)
? @@( o1.Content() )
#--> [ [ "name", "Aya" ], [ "age", 5 ], [ "city", "Niamey" ] ]
```
composed from the signature, run for this page

UpdateNthKey Replace the KEY of the nth pair (mutating). in stzHashList

composed example

o1 = new stzHashList([ :name = "Aya", :age = 30, :city = "Niamey" ])
o1.UpdateNthKey(2, "a")
? @@( o1.Content() )
#--> [ [ "name", "Aya" ], [ "a", 30 ], [ "city", "Niamey" ] ]

composed from the signature, run for this page

ReplaceNthKey Replace the key of the nth pair (mutating). in stzHashList

composed example

o1 = new stzHashList([ :name = "Aya", :age = 30, :city = "Niamey" ])
o1.ReplaceNthKey(2, "AN")
? @@( o1.Content() )
#--> [ [ "name", "Aya" ], [ "AN", 30 ], [ "city", "Niamey" ] ]

composed from the signature, run for this page

ReplaceLastKey Replace the key of the last pair (mutating). in stzHashList

composed example

o1 = new stzHashList([ :name = "Aya", :age = 30, :city = "Niamey" ])
o1.ReplaceLastKey("AN")
? @@( o1.Content() )
#--> [ [ "name", "Aya" ], [ "age", 30 ], [ "AN", "Niamey" ] ]

composed from the signature, run for this page

and 44 more in the reference

Removing

StripNulls Remove the null items from the list (mutating). in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.StripNulls()
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]
```
composed from the signature, run for this page
TrimToSize Cut the list down to its first n items (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.TrimToSize(2)
? @@( o1.Content() )
#--> [ 5, 3 ]
```
composed from the signature, run for this page
RemoveFirst remove the first occurrence of pItem in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveFirst(3)
? @@( o1.Content() )
#--> [ 5, 8, 3, 1 ]
```
composed from the signature, run for this page
RemoveRange RemoveRange: remove items from start for a count in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveRange(2, 5)
? @@( o1.Content() )
#--> [ 5 ]
```
composed from the signature, run for this page
RemoveSpaces RemoveSpaces / RemoveSpacesQ: drop every " " item (string-space) from the content. Engine-aware: only removes string-typed " ". in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.RemoveSpaces()
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]
```
composed from the signature, run for this page
RemoveNthItem remove the item at position n; accepts :First / :Last in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveNthItem(2)
? @@( o1.Content() )
#--> [ 5, 8, 3, 1 ]
```
composed from the signature, run for this page

RemoveNumbers Remove all the number items (mutating). in stzList

composed example

o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.RemoveNumbers()
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]

composed from the signature, run for this page

RemoveSection RemoveSection: remove items between two positions in stzList

o1 = new stzList([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ])
o1.RemoveSection(3, 8)
# removesection example 1
? @@( o1.Content() )
#--> [ 1, 2, 9, 10 ]

library test

RemoveFirstItem RemoveFirstItem / RemoveLastItem Remove the first item of the list (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveFirstItem()
? @@( o1.Content() )
#--> [ 3, 8, 3, 1 ]
```
composed from the signature, run for this page
RemoveDupOrigins Remove the first occurrence of each duplicated item (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveDupOrigins()
? @@( o1.Content() )
#--> [ 5, 8, 3, 1 ]
```
composed from the signature, run for this page

RemoveOccurrences remove the panOcc-th occurrences of pItem (by occurrence index) in stzList

o1 = new stzList([ "a", "b", "a", "a", "c", "d", "a" ])
o1.RemoveOccurrences([ 4, 1, 3 ], "a")
? o1.Content()
#--> b
#--> a
#--> c
#--> d

library test

RemoveThisNthItem remove the n-th occurrence of pItem in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RemoveThisNthItem(2, 3)
? @@( o1.Content() )
#--> [ 5, 3, 8, 1 ]
```
composed from the signature, run for this page

and 33 more in the reference

Adding

AddItem Add the given item at the end of the list (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.AddItem(3)
? @@( o1.Content() )
#--> [ 5, 3, 8, 3, 1, 3 ]
```
composed from the signature, run for this page
AddItems adding many items to the list in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.AddItems([ 2, 3 ])
? @@( o1.Content() )
#--> [ 5, 3, 8, 3, 1, 2, 3 ]
```
composed from the signature, run for this page
ExtendTo Sugar aliases over ExtendToPositionXT: the same operation but using the more natural "ExtendTo" / "Extend" naming. Default filler is the empty string. in stzList
```
o1 = new stzList([ "A", "B", "C" ])
o1.ExtendTo(5)
? @@( o1.content() )
#--> [ "A", "B", "C", "", "" ]
```
library test

InsertAt InsertAt: insert an item at a given position in stzList

o1 = new stzList([ "A", "C", "D" ])
o1.InsertAt(2, "B")
? o1.Content()
#--> A
#--> B
#--> C
#--> D

library test

AddItemAt adding an item at a given position --> insert or extend in stzList

o1 = new stzList(1:5)
o1.AddItemAt(8, 9)
? @@( o1.Content() )
#--> [ 1, 2, 3, 4, 5, "", "", 9 ]

library test

InsertAfter InsertAfter(:ItemAtPosition = n, item): NON-mutating -- returns the -- would-be list with item inserted after position n, leaving This as-is -- (use InsertAfterPosition for the mutating form). in stzList
```
o1 = new stzList([ "A1", "A2", "A3" ])
o1.InsertAfter( :ItemAtPosition = 3, "A4" )
? o1.Content()
#--> A1
#--> A2
#--> A3
```
library test
ExtendToPosition Extend the list up to position n. ExtendToPosition pads with 0 -- (number lists) or "" ; the WithItemsIn/Repeated forms pad by -- cycling through a given list (or the list's own items). in stzList
```
o1 = new stzList([ 1, 2, 3])
o1.ExtendToPosition(5)
? @@( o1.Content() )
o1.ExtendToPositionXT( 8, :With = 5 )
? @@(o1.Content())
#--> [ 1, 2, 3, 0, 0 ]
#--> [ 1, 2, 3, 0, 0, 5, 5, 5 ]
```
library test
InsertAfterPosition inserting an item after a given position in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.InsertAfterPosition(2, 3)
? @@( o1.Content() )
#--> [ 5, 3, 3, 8, 3, 1 ]
```
composed from the signature, run for this page
InsertBeforePosition inserting an item before a given position in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.InsertBeforePosition(2, 3)
? @@( o1.Content() )
#--> [ 3, 5, 3, 8, 3, 1 ]
```
composed from the signature, run for this page
InsertBeforePositions Insert the item before EACH of the given positions (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.InsertBeforePositions([ 2, 3 ], 3)
? @@( o1.Content() )
#--> [ 5, 3, 3, 3, 8, 3, 1 ]
```
composed from the signature, run for this page

InsertAfterManyPositions insert after/before many positions / by w-condition in stzList

o1 = new stzList([ "a", "b", "c", "d", "e" ])
o1.InsertAfterManyPositions([ 2, 4, 5 ], "*")
? @@( o1.Content() )
#--> [ "a", "b", "*", "c", "d", "*", "e", "*" ]

library test

InsertBeforeManyPositions insert after/before many positions / by w-condition in stzList

o1 = new stzList([ "a", "b", "c", "d", "e" ])
o1.InsertBeforeManyPositions([ 2, 4, 5 ], "*")
? @@( o1.Content() )
#--> [ "a", "*", "b", "c", "*", "d", "*", "e" ]

library test

and 25 more in the reference

Splitting and extracting

SplitW SplitW MUTATES the content into the list of parts (the matching items are dropped; SplittedW is the passive twin). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.SplitW("@item > 3") )
#--> [ [ 3 ], [ 3, 1 ] ]
```
composed from the signature, run for this page
SplitAt SplitAt (engine-backed) Split the list at the given cut position(s): the parts. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.SplitAt(2) )
#--> [ [ 5 ], [ 3, 8, 3, 1 ] ]
```
composed from the signature, run for this page

ExtractAll Empty the list, returning everything that was in it. in stzList

o1 = new stzList([ "A", "B", "C" ])
# extractall example 1
? @@( o1.ExtractAll() )
# extractall example 2
? @@( o1.Content() )
#--> [ "A", "B", "C" ]
#--> [ ]

library test

ExtractNth Remove the nth item and return it. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.ExtractNth(2)
#--> 8
```
composed from the signature, run for this page
SplitAfter Split the list after each occurrence of the item: each occurrence closes its part. in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.SplitAfter(3)
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]
```
composed from the signature, run for this page

ExtractLast Remove the LAST occurrence of the item and return it. in stzList

o1 = new stzList([ "A", "B", "C", "_" ])
? o1.ExtractLast("_") + NL
? o1.Content()
#--> _
#--> A
#--> B
#--> C

library test

SplitBefore Split the list before each occurrence of the item: each occurrence starts a new part. in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.SplitBefore(3)
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]
```
composed from the signature, run for this page

ExtractFirst Remove the FIRST occurrence of the item and return it. in stzList

o1 = new stzList([ "_", "A", "B", "C" ])
? o1.ExtractFirst("_") + NL
? o1.Content()
#--> _
#--> A
#--> B
#--> C

library test

SplitAtPacer splitting using a given pacer in stzList

composed example

o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.SplitAtPacer(2, 5)
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]

composed from the signature, run for this page

SplitToNParts Split the list into n (near-)equal parts. in stzList

o1 = new stzSplitter(3)
? @@( o1.SplitToNParts(0) )
o1 = new stzList([ "A", "B", "C" ])
? @@( o1.SplittedToNParts(3) )
#--> [ ]
#--> [ [ "A" ], [ "B" ], [ "C" ] ]

library test

ExtractSection Remove the items at positions n1..n2 and return them. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.ExtractSection(2, 5) )
#--> [ 3, 8, 3, 1 ]
```
composed from the signature, run for this page
SplitAtPosition Split the list at the given position: the parts. in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
o1.SplitAtPosition(2)
? @@( o1.Content() )
#--> [ "tea", "rice", "tea", "fish" ]
```
composed from the signature, run for this page

and 32 more in the reference

Ordering and moving

Move Move / Swap accept the named-param spellings Move(:ItemFromPosition = a, :To = b), Swap(:Positions = a, :And = b), and the value form Swap(item1, :And = item2). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.Move(2, 5)
? @@( o1.Content() )
#--> [ 5, 8, 3, 1, 3 ]
```
composed from the signature, run for this page

Sort Sort the items in ascending order in place (mutating). For a copy, use Sorted. in stzList

? @@( StzListQ([ "him", [ "him" ], "" ]).Sorted() ) + NL
o1 = new stzList([ "him", [ "him" ], "" ])
o1.Stringify()
? @@( o1.Content() )
o1.Sort()
#--> [ "", "him", [ "him" ] ]
#--> [ "him", '[ "him" ]', "" ]

library test

Swap Exchange the items at the two given positions (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.Swap(2, 5)
? @@( o1.Content() )
#--> [ 5, 1, 8, 3, 3 ]
```
composed from the signature, run for this page

SortBy Sort by a key expression (engine-backed via the W DSL). in stzList

o1 = new stzList([ "a", "abcde", "abc", "ab", "abcd" ])
o1.SortBy('len(@item)')
# sortby example 1
? @@( o1.Content() )
#--> [ "a", "ab", "abc", "abcd", "abcde" ]

library test

Reverse Reverse the order of the items in place (mutating). For a copy, use Reversed. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.Reverse()
? @@( o1.Content() )
#--> [ 1, 3, 8, 3, 5 ]
```
composed from the signature, run for this page
MoveToEnd Move the item at position n to the END of the list (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.MoveToEnd(2)
? @@( o1.Content() )
#--> [ 5, 8, 3, 1, 3 ]
```
composed from the signature, run for this page
RotateLeft rotate -- circular shift in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RotateLeft(2)
? @@( o1.Content() )
#--> [ 8, 3, 1, 5, 3 ]
```
composed from the signature, run for this page
SortOnDown SortOnDown / SortedOnDown for stzList: when the list is flat (numbers / strings), forwards to descending sort on the whole list. When the list is a list-of-lists, forwards to the stzListOfLists.SortOnDown(n) which sorts on column n. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.SortOnDown(2)
? @@( o1.Content() )
#--> [ 8, 5, 3, 3, 1 ]
```
composed from the signature, run for this page
MoveToStart Move the item at position n to the START of the list (mutating). in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.MoveToStart(2)
? @@( o1.Content() )
#--> [ 3, 5, 8, 3, 1 ]
```
composed from the signature, run for this page
RotateRight rotate -- circular shift in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.RotateRight(2)
? @@( o1.Content() )
#--> [ 3, 1, 5, 3, 8 ]
```
composed from the signature, run for this page
MoveItemToEnd move item by value in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.MoveItemToEnd(3)
? @@( o1.Content() )
#--> [ 5, 8, 3, 1, 3 ]
```
composed from the signature, run for this page
MoveItemToStart move item by value in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
o1.MoveItemToStart(3)
? @@( o1.Content() )
#--> [ 3, 5, 8, 3, 1 ]
```
composed from the signature, run for this page

and 20 more in the reference

Converting

ToString ToString: a plain display form -- the items rendered one per line (monolith semantics: ToStringXT(:ConcatenatedUsing = NL)). Overrides the stzObject default so a stzList stringifies to its content, not to an "@noname" object handle. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? o1.ToString()
#--> 5
#--> 3
#--> 8
#--> 3
#--> ...
```
composed from the signature, run for this page
ToListInAString ToListInAString: the content rendered as a "[ ... ]" string (computable form). Delegates to stzListStringify, like the rest of this section. in stzList
```
? @@( StzListQ( 4:8 ).ToListInAString() )
? @@( StzListQ( 4:8 ).ToListInAStringInShortForm() )
#--> "[ 4, 5, 6, 7, 8 ]"
#--> "4:8"
```
library test
ToListOfStzStrings tion over the established per-string locale lookups. in stzList
composed example
```
o1 = new stzList([ "tea", "rice", "tea", "fish" ])
? @@( o1.ToListOfStzStrings() )
#--> [ @noname, @noname, @noname, @noname ]
```
composed from the signature, run for this page
ToListInAStringInShortForm Short form: a contiguous run of integers (a, a+1, ..., b -- or the descending a, a-1, ..., b) collapses to the range literal "a:b". Anything else falls back to the full stringified list. in stzList
```
? StzListQ( 4:8 ).ToListInString()
? StzListQ( 4:8 ).ToListInStringInShortForm()
#--> [ 4, 5, 6, 7, 8 ]
#--> 4:8
```
library test

ToCode The hash list as runnable Haro code, as a string. in stzHashList

composed example

o1 = new stzHashList([ :name = "Aya", :age = 30, :city = "Niamey" ])
? o1.ToCode()
#--> [ :name = "Aya", :age = "30", :city = "Niamey" ]

composed from the signature, run for this page

ToStzHashList content access in stzListNamedParams
ToStzTable The list turned into a stzTable object (rows; per the stzTable contract, the first row may carry the column names). in stzList
ToStzListOfStrings Convert to a stzListOfStrings (for string-oriented chaining like -- ConcatenatedUsing / Joined). Needed by the ..Q() chain idioms. in stzList
ToStzSetOfSections transforming the list of pairs into a stzhashlist in stzListOfPairs
ToStzListOfSections transforming the list of pairs into a stzhashlist in stzListOfPairs
Parse parsing in stzListParser
ToStzList utility functions used by the other methods above in stzSplitter

and 3 more in the reference

Showing, drawing and formatting

Show Print the list to stdout in its computable @@ form. in stzList
ShowShort Print an abbreviated form of the list (first items ... last items). in stzList
ShowShortN Print the abbreviated form showing n items at each end. in stzList

Walking and applying

Map expression-backed operations (engine bytecode) in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.Map("@item > 3") )
#--> [ 1, 0, 1, 0, 0 ]
```
composed from the signature, run for this page
WalkW Walk the list collecting where the W condition holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkW("@item > 3") )
#--> [ 1, 3 ]
```
composed from the signature, run for this page
Filter expression-backed operations (engine bytecode) in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.Filter("@item > 3") )
#--> [ 5, 8 ]
```
composed from the signature, run for this page
WalkWhen The When-walk over the items (see stzListWalker), driven by the given condition. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkWhen("@item > 3") )
#--> [ 1, 2, 3, 4, 5 ]
```
composed from the signature, run for this page
WalkUntil Walk the items UNTIL the given condition holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkUntil("@item > 3") )
#--> [ 1 ]
```
composed from the signature, run for this page
WalkWhere Walk the list collecting where the condition holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkWhere("@item > 3") )
#--> [ 1, 3 ]
```
composed from the signature, run for this page
WalkWhile Walk the items WHILE the given condition holds. in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkWhile("@item > 3") )
#--> [ 1 ]
```
composed from the signature, run for this page
WalkFromTo PositionsWhere already defined above as alias of FindAllItemsW in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkFromTo(2, 5) )
#--> [ 2, 3, 4, 5 ]
```
composed from the signature, run for this page
WalkZigZag walking in zigzag pattern in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkZigZag(2) )
#--> [ 1, 3, 5, 5, 3, 1 ]
```
composed from the signature, run for this page
WalkEveryNth walking every nth position in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkEveryNth(2) )
#--> [ 2, 4 ]
```
composed from the signature, run for this page
WalkNForward walking the list n items forward in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkNForward(2) )
#--> [ 1, 3, 5 ]
```
composed from the signature, run for this page
WalkSkipping walk skipping n items in stzList
composed example
```
o1 = new stzList([ 5, 3, 8, 3, 1 ])
? @@( o1.WalkSkipping(2) )
#--> [ 1, 4 ]
```
composed from the signature, run for this page

and 19 more in the reference

The explanations are the ones the library gives of itself, read from its documentation comments on 2026-10-01 04:14, from the library at commit 0e72e2e2c, by the library's own stzSelfDoc over 635 class sources.

The classes of this area

stzListNamedParams · 1365 methods
stzList · 887 methods
stzHashList · 221 methods
stzGrid · 196 methods
stzListOfPairs · 98 methods
stzFalseObject · 56 methods
stzListRandom · 45 methods
stzListChecker · 41 methods
stzListOfLists · 41 methods
stzYielder · 38 methods
stzListReplacer · 37 methods
stzListSorter · 36 methods
stzListFlattener · 35 methods
stzForEachObject · 34 methods
stzItemCS · 34 methods
stzTree · 34 methods
stzListParser · 32 methods
stzSplitter · 31 methods
stzListFinder · 30 methods
stzLog · 28 methods
stzListClassifier · 25 methods
stzListGetter · 25 methods
stzListMerger · 25 methods
stzListRemover · 25 methods

Collections & objects

The functions, by what they do

Testing and checking

Finding

Counting and measuring

Replacing and setting

Removing

Adding

Splitting and extracting

Ordering and moving

Converting

Showing, drawing and formatting

Walking and applying

The classes of this area

Narrations about this area